I got this coin about a week ago and have been scratching my head. I have 6 others very similar, fully red from 1976 and 1979. The person I purchased them from took them from mint rolls whilst working at the bank in the late 70's.
This is unlike any error I have taken notice of before. I'll let the photos do the talking because I dont know how to best describe it.
The only piece of information I will add is that on the edge the 'ledge'? goes all the way around the coin.
The images may originally appear small but if you click on them they enlarge in a new window/tab. Sorry i havent got around to investigating and external photo hosting site yet.
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Wait and see what answers get posted here now.
It's what I call a railroad rim, a partial collar error.
Thanks PPH!
There was a straight, partial collar on eBay recently -20¢ I think. The seller said he had never seen anything like it and didn't know what to call it so he christened it the "flywheel". Good name I say (if you are familiar with a typical car flywheel).
That comparison isnt quite as good for this 2c due to the absence of reeding. It is good for coins with reeding though. That probably the best description ive heard.